The present invention relates to an electrooptic device, for example, such as a liquid crystal device, an EL (electroluminescence) display device, PDP (plasma display panel), or the like. The present invention also relates to an electronic apparatus comprising the electrooptic device.
At present, an electrooptic device for displaying information such as characters, figures, patterns, etc. is widely used in an electronic apparatus such as a portable telephone, a personal digital assistant, and the like.
In a liquid crystal device as an example of such electrooptic devices, for example, scanning electrodes formed on one of substrates and selective (data) electrodes formed on the other substrate are crossed each other at a plurality of points in a dot matrix to form a plurality of pixels. A liquid crystal is sealed between both substrates so that light passing through the liquid crystal in each of the pixels is modulated by selectively changing the voltage applied to each of the pixels to display an image such as a character or the like. A so-called reflective or transflective liquid crystal device uses a metal which is also used as a reflecting plate as a material for the scanning electrodes or the selective electrodes, and particularly aluminum is selected as a preferred material for the electrode material.
On the other hand, in the electrooptic device, in order to secure a portion of connection with electrooptic device driving IC, or an external circuit additionally connected to another electrooptic panel, the scanning electrodes or the selective electrodes are extended to the end of one of the substrates to secure connecting terminals for securing connection with the external circuit. Also a thermal compression bonding method using ACF (anisotropic conductive film) is known as the method of connecting the connecting terminals of the electrooptic panel with the external circuit.
However, in using aluminum for the scanning electrodes or the selective electrodes, the connecting terminals are made of aluminum, and thus the quality of connection mounting in the connecting step using ACF cannot be easily recognized, thereby causing the problem of failing to secure the reliability of the electrooptic device.
Namely, with the connecting terminals comprising transparent electrodes made of ITO or the like, the state of ACF can be easily observed from the back of one of the substrates, and a decision can relatively easily be made as to whether or not the connection state is good. However, with the connecting terminals made of aluminum, the connecting terminals are opaque, and the state of ACF cannot be easily observed from the back of the substrate.
It is an object of the present invention to provide an electrooptic device permitting recognition of a connection state using ACF and having high reliability, and an electronic apparatus comprising the electrooptic device.
As means for achieving the object of the present invention, an electrooptic device of the present invention comprises a transparent substrate and a counter substrate opposed to each other and comprising electrodes formed on the opposed surfaces thereof, an overhang portion provided on the transparent substrate to overhang outward from the counter substrate, connecting terminals made of aluminum and formed on the overhang portion to be electrically connected to the electrodes, a connection portion of an external circuit electrically connected to the connecting terminals through an anisotropic conductive film, wherein nicks or gouges formed by conductive particles contained in the anisotropic conductive film and cutting into the connecting terminals are visible through the transparent substrate.
In the electrooptic device, the nicks or gouges formed by the conductive particles contained in the anisotropic conductive film and cutting into the connecting terminals are visible through the transparent substrate, and thus the connecting terminals can be observed through transparent electrodes after the connection portion of the external circuit is connected to the connecting terminals in the manufacturing process to permit a decision as to whether or not the connection state is normal.
The connecting terminals may be formed to a thickness of 0.01 to 0.5 xcexcm.
In this case, the connection state between the connection portion of the external circuit and the connecting terminals can be improved, and the nicks or gouges can easily be observed.
The penetration amount of the nicks or gouges may be 0.01 xcexcm or more.
In this case, the connection state between the connection portion of the external circuit and the connecting terminals can be improved, and the nicks or gouges can easily be observed.
In the area of the nicks or gouges, the connecting terminals may have a thickness of 0.5 xcexcm or less.
In this case, the nicks or gouges can easily be observed.
The electrooptic device may be used as a liquid crystal device.
The method of manufacturing an electrooptic device of the present invention comprising a transparent substrate and a counter substrate opposed to each other and comprising electrodes formed on the opposed surfaces thereof, an overhang portion provided on the transparent substrate to overhang outward from the counter substrate, connecting terminals made of aluminum and formed on the overhang portion to be electrically connected to the electrodes, and a connection portion of an external circuit electrically connected to the connecting terminals through an anisotropic conductive film, the method comprising the step of heating the anisotropic conductive film and compression-bonding the connecting terminals and the connection portion of the external circuit to electrically connect the connecting terminals to the connection portion of the external circuit, and the step of deciding the connection state between the connecting terminals and the connection portion of the external circuit based on the presence of nicks or gouges formed by the conductive particles contained in the anisotropic conductive film and cutting into the connecting terminals.
In the method of manufacturing the electrooptic device, the connection state between the connecting terminals and the connection portion of the external circuit is decided based on the presence of the nicks or gouges formed by the conductive particles contained in the anisotropic conductive film and butting into the connecting terminals, and the connection state between the connecting terminals and the external circuit can easily and securely be decided.
An electronic apparatus of the present invention comprises the electrooptic device as the above-described means.
In the electronic apparatus, the nicks or gouges formed by the conductive particles contained in the anisotropic conductive film and butting into the connecting terminals are visible through the transparent substrate, and thus the connecting terminals can be observed through transparent electrodes after the connection portion of the external circuit is connected to the connecting terminals in the manufacturing process to permit a decision as to whether or not the connection state is normal.